Shock absorber for pumping equipment



Nov. l0, 1964 R, c, MASQN 3,156,459

SHOCK ABSORBER FOR PUMPING EQUIPMENT Filed Nov. 13, 1962 Illluullllll IlIlIIIIH ,M

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AWC/mrd C Naso/7 BY TTOR/VEY United States Patent O Ficel 3,156,459 SHOCK ABSORBER FOR PUMPING EQUIPMENT Richard C. Mason, 1124 S. Guthrie St., Tulsa, Okla. Filed Nov. '13, 1962, Ser. No. 236,974 4 Claims. (Cl. 267-70) This invention relates to shock absorbers for reducing breakage of the sucker rods and damage to the pumping equipment used in pumping oil and other liquids from the ground.

In pumping oil and similar Wells, a reciprocatory pumping jack is usually employed for raising the rods on the upstroke of the pump in the Well, while gravity is depended upon for producing the downstroke. The shock resulting from changing direction in travel of the rods produces considerable buckling and bending of the rods that results in fatigue and breakage of the rods and damage to the pumping equipment.

Various types of shock absorbers have been devised in an attempt to eliminate these diiliculties, one of the most effective of which is the shock absorber illustrated in Patent No. 2,241,409, issued to me on May 13, 1941. The shock absorber covered in this patent includes a plurality of hollow resilient cushioning members interposed between plates, one of which is carried by the rod hanger of the pumping jack, and the other is attached to the rods in such a manner that the weight of the rods is resiliently supported upon the cushioning members. However, changing the direction of the stroke under power of the pumping jack and the forces of gravity causes the cushioning members to work and generate considerable internal heat that accumulates therein and affects the resiliency and life thereof, so that the cushioning members cannot be depended upon to function efficiently over a time sufficient for the shock absorber to be economical.

It is, therefore, a principal object of the present invention to provide for cooling the cushioning members by creating a flow of air therethrough under the working action thereof. p

In the shock absorber of the present invention this is accomplished by providing resilient cushioning members with open ends that register with apertures in the plates, whereby the cushioning members, when under greatest compression during lift of the rods, expel air from the interior thereof, and draw air into the cushioning members when the cushioning members expand under the reduction in load which takes place on the downstroke of the rods. Thus a constant flow of air is maintained into and out of the cushioning members, to carry away internal heat involved in the working of the cushioning members. Venting of the cushioning members makes them more resilient, and in order to brace them under an increasing load, means is provided on the cushioning members to make Contact with each other in such a manner that the cushioning members brace eachother, to thereby withstand greater load while at the same time providing for iiow of the cooling air.

Also, means is provided on the polish rod clamp to bear upon the upper plate member at a plurality of points remote from the polish rod, and thereby help stabilize the upper plate member under the greater resiliency of the cushioning members.

In accomplishing this object I have provided improved structure, the preferred form of which is illustrated in ,the accompanying drawings, wherein:

FIG. 1 is a perspective view of a shock absorber constructed in accordance with the present invention.

FIG. 2 is a vertical cross sectional View through the shock absorber, taken on line 2-2 of FIG. 4.

FIG. 3 is a cross section through the polish rod section .of the pump rod, illustrating the polish rod clamp for applying load of the rods on the upper plate.

3,156,459 Patented Nov. 10, 1964 FIG. 4 is a cross section through the shock absorber on the line 4-4 of FIG. 2.

FIG. 5 is a perspective view of one of the cushioning members.

Referring more in detail to the drawings:

1 designates the polish rod section of a string of sucker rods, and 2 and 3 designate the side rods of the hanger of a pumping jack (not shown) by which the rods are reciprocated in a manner well known in the art of pumping wells. The hanger rods 2 and 3 and polish rod 1 are interconnected by a shock absorber 4 embodying the features of the present invention.

The shock absorber 4 includes a lower plate member 5 having right and left wing portions 6 and 7 of generally Octagon shape and integrally connected in spaced relation by a bridge 8, to provide a space 9 therebetween to accommodate the polish rod 1 in the axial center of the plate, as best shown in FIG. 4. The right and left wing portions of the plate on opposite sides of the polish rod are provided with inwardly extending notches 10 and 11 to accommodate the hanger rods 2 and 3 therein. The wing portions 6 and 7 of the plate have upwardly extending anges 12 and 13 extending around the notches to provide seats 14 and 15 -tor the hanger rods 2 and 3, and to provide guides for an upper plate member 16, to be later described.

The wing portions of the plate member have upper and lower marginal anges 17 and 18. Distributed over the upper face of the wing portions, and connected with the flanges 17 and with each other by webs 19 are a plurality of individual circular flanges 20 to form upwardly facing sockets or seats 21, each having an aperture 22 (FIG. 2) extending completely through the plate member.

The upper plate member 16 follows the general shape of the lower member and has laterally spaced apart wing portions 23 and 24, each provided with an inwardly extending notch 25-26 (FIG. 1) registering with the notches 10 and 11 of the lower plate member 5, but of sufficient width to be slidable upon the upper ends of the flanges or guides 12 and 13. The upper plate member 16 is thus retained from turning movement with respect to the lower plate member 5 by the guides 12-13,.but can move to and from the lower member 5 to accommodate the cushioning members 27 therebetween, as later described. j

The wing portions 23 and 24 are spaced apart similar to the lower wing portions, to provide a notch or recess 28 corresponding to the space 9 in the lower plate member. Formed about the marginal edges of the wing portions 23 and 24 and depending from the bottom faces thereof are depending flanges 29 encompassing a plurality of depending circular flanges 30 (FIG. 2) corresponding in number and arrangement with the circular flanges 20 of the lower plate member, to provide downwardly facing sockets or seats 31, having a centralaperture 32 extending completely through the depth of the wing portions 23 and 24. The upper faces of the wing portions have upwardly extending marginal flanges 33 following the contour thereof except for gaps 34 to accommodate the upstanding flanges or guides 12 and 13.

The cushioning members 27 have preferably barrel shaped bodies 35 formed of resilient material, such as rubber, synthetic rubber, or the like, and have annular walls 36 to provide an internal air compartment 37. The lower and upper cylindrical ends 38-39 of the walls are of a diameter and shape to closely tit within the sockets 21 and 31 that have been provided in the lower and upper plate members 7 and 16. The ends are closed by integral heads 4t) and 41 which are provided with apertures 42 and 43 that register, respectively, with the apertures 22 and 23 of the plate members. The central part of the body of each cushioning member is encircled by a reinforcing rib 44. The rib 44 on one cushioning member makes contact with the ribs of the adjacent cushioning members, as shown in FIGS. 2 and 4.

45 designates a polish rod clamp composed of two members 46 and 47. Each member has a substantial semicircular collar 48 for embracing one side of the polish rod. The collars terminate in oppositely projecting flanges 49 and 50. Each flange has openings to pass fastening devices, such as bolts 5l. Extending radially outwardlyk and downwardly from each collar portion are legs 52, terminating in feet 53 located over the wing portions 23 and 24 of the upper plate member. Each foot 53 preferably has an internally threaded opening S4 therein. Adjustably mounted in the openings 54 are set screws 55 to bear upon the upper face of the upper plate member of the shock absorber. The ends 56 of the hanger rods 2 and 3 are threaded, as at 57, to mount nuts 58 for backing washers 59 on which the lower plate member 5 of the shock absorber is to be supported.

In assembling the shock absorber, the lower ends 38 of the cushioning members 27 are seated within the sockets 21 of the lower plate member 5. The upper plate member 16 is then seated over the upper ends 39 of the cushioning members, with the ends 39 passing into the sockets 31 of the upper plate member as the upper plate member is guided onto the anges or guides 12 and 13.

The shock absorber thus far assembled is applied to the lower ends of the hanger rods 2 and 3, so that it is supported upon the washers 59 that are backed by the nuts 58, as best shown in FIG. 2. The hanger rods 2 and 3 are kept within their seat by pins 60 inserted across the open side of the guides. The assembly is then placed over the polish rod 1, with the polish rod passing into the inwardly extending spaces 9 and Z8 so that it is seated against the bridges 8 of the plate members.

The polish rod clamp, composed of the members 46 and 47, is then assembled on the polish rod over the upper plate member 16 so that the `Set screws 5S bear upon the wings of the upper plate member at opposite sides of the guide flanges and at a distance from the polish rod, in which position the bolts 51 are tightened to firmly secure the clamp to the polish rod, in which position the string of rods connected to the polish rod are suspended from the upper plate, which in turn is supported by the lower plate member 5 through the cushioning members 27, the lower plate member being in turn suspended from the pumping jack, not shown, by means of the hangers 2 and 3. If all of the set screws do not contact the wings of the upper plate member, they are adjusted until they seat equally thereupon.

It is obvious that with the shock absorber mounted as described, the entire weight of the sucker rods, including the weight of the fluid in the pump tubing, is resilient- 1y carried by the cushion members, so that the cushioning members are somewhat compressed under the load. When the pumping jack (not shown) is in operation, the cushioning members work to absorb and relieve the sucker rods from shock. On the upstroke, the hangers 2 and 3 will lift the lower plate member 5 of the shock absorber, further compressing the cushioning members under lifting power of the pumping jack, so that air within the internal compartments 37 of the cushioning members is discharged through the apertures 42 and 43 and through the registering apertures 22 and 32 of the plate members 5 and 16.

On the downstroke of the pump, when the downward movement of the rods is under gravity, the load acting on the cushioning members is reduced to permit expansion thereof and drawing in of air through the registering apertures 32, 43 and 22, 42 to fill the internal compartments 37 of the cushioning members.

It is thus obvious that with each complete stroke of the pump, the working of the cushioning members in absorbing shock on the rods results in a constant ow of air m'to and out of the cushioning members, to cool and carry away the internal heat caused by the internal working action thereof.

By keeping the cushioning members with the constant flow of air, the cushioning members are enabled to stand up under the internal friction and the heat normally resulting therefrom. Also, the cushioning members are kept more resilient and a smoother action results from the easy snubbing action resulting from the internal flow of air, which action greatly prolongs the life of the sucker rods. lt is obvious that venting of the cushioning members makes them more resilient, but they are strengthened as the load increases since contact of the ribs 44 of one cushioning member with the ribs of the adjacent cushioning members braces the cushioning members to withstand the necessary load. Also, the bearing of the polish rod clamp upon the wings of the upper plate member tends to stabilize the upper plate member under the greater' resilient action of the cushioning members.

While the shock absorber is described as being mounted between the polish rod and hanger, it may be inserted in other positions, such as between the walking beam of the pumping jack and pitman stirrup that actuates the walking beam. The shock absorber may be made of various sizes and equipped with a suitable number of the cushioning members for adequately supporting the load and to give the necessary shock absorbing action under the conditions to be encountered.

What I claim and desire to secure by Letters Patent is:

l. A shock absorber for connecting a variable ioad with a reciprocating means, said shock absorber including a plate member to be connected with the reciprocating means and having vertical guides,

a plate member to be connected with the variable load and having portions in sliding engagement with the guides,

said plate members having registering sockets in facing sides thereof and apertures registering with said sockets,

cushioning members between the plate members and having hollow bodies with cylindrical ends closely fitting within said sockets to expand and compress under relative movement of the plate members for absorbing shocks,

said cylindrical ends of the cushioning members having apertures registering with the apertures in the plate members for flow of air into and out of the cushioning members for cooling said cushioning members, and

said cushioning members having circumferential ribs with the ribs of one member contacting with the ribs of adjacent members under said variable load for strengthening support of the cushioning members under increased resiliency afforded by flow of air therefrom.

2. A shock absorber for connecting a pumping jack with a polish rod in a pumping apparatus, said shock absorber including a lower plate member to be connected with the pumping jack,

an upper plate member,

said plate members having a plurality of registering sockets in facing sides thereof and apertures registering with said sockets and of less diameter to provide annular seats encircling the apertures,

resilient hollow cushioning members between the plate members and having ends closely fitting within said sockets and engaging the annular seats to expand and compress under a variable load on the plate members,

said ends of the cushioning members having apertures registering with the apertures in the plate members for flow of air into and out of the cushioning members under expansion and compression thereof for disposing of internal heat resulting from working of said cushioning members, and

a polish rod connector above the upper plate member and having a plurality of outwardly projecting arms provided with means in bearing contact upon the upper plate member at distances remote from the polish rod to stabilize the upper plate member under the greater resiliency of the cushioning members afforded by venting the cushioning members through said apertures.

3. A shock absorber for connecting rod hangers of a pumping jack with a polish rod of a pumping apparatus, said shock absorber including a plurality of resilient cushioning members having hollow bodies providing compartments for containing air and having ends provided with apertures in connection with said compartments,

upper and lower plate members having laterally spaced apart wing portions for the polish rod to pass therebetween and each wing portion having oppositely opposed inwardly extending slots for the hangers to extend therethrough in supporting the lower plate member by said hangers,

said wing portions of the upper and lower plate members having registering sockets in facing sides thereof seating the ends of the cushioning members therein and having apertures registering with the apertures in the ends of said cushioning members through which the compartments of said cushioning members are vented,

a polish rod connector above the upper plate member and having outwardly and downwardly extending legs terminating in feet located over said wing portions, and

set screws adjustably carried in said feet and bearing upon the wing portions of the upper plate member whereby load on the polish rod is applied to said wing portions of the upper plate member remotely from the polish rod to stabilize the upper plate member under the resiliency of the cushioning memi opposed inwardly extending notches for the hangers to extend therebetween in supporting the lower piate member by said hangers,

upstanding guide flanges extending about marginal edges of the notches of the lower plate member and projecting through the notches of the upper plate member for slidably mounting the upper plate member thereon,

said wing portions of the upper and lower members having registering sockets in facing sides thereof seating the ends of the cushioning members therein and having apertures registering with the apertures in the ends of said cushioning members through which the compartments of said cushioning members are Vented,

a polish rod connector above the upper plate member and having outwardly and downwardly extending legs terminating in feet located over the wing portions on opposite sides of the guide flanges, and

set screws adjustably carried in said feet and bearing upon the wing portions of the upper plate member whereby load on the polish rod is applied to the wing portions on opposite sides of the guide flanges for stabilizing the upper plate member under the resiliency of the cushioning members afforded by venting of said compartments.

References Cited in the tile of this patent UNITED STATES PATENTS 

1. A SHOCK ABSORBER FOR CONNECTING A VARIABLE LOAD WITH A RECIPROCATING MEANS, SAID SHOCK ABSORBER INCLUDING A PLATE MEMBER TO BE CONNECTED WITH THE RECIPROCATING MEANS AND HAVING VERTICAL GUIDES, A PLATE MEMBER TO BE CONNECTED WITH THE VARIABLE LOAD AND HAVING PORTIONS IN SLIDING ENGAGEMENT WITH THE GUIDES, SAID PLATE MEMBERS HAVING REGISTERING SOCKETS IN FACING SIDES THEREOF AND APERTURES REGISTERING WITH SAID SOCKETS, CUSHIONING MEMBERS BETWEEN THE PLATE MEMBERS AND HAVING HOLLOW BODIES WITH CYLINDRICAL ENDS CLOSELY FITTING WITHIN SAID SOCKETS TO EXPAND AND COMPRESS UNDER RELATIVE MOVEMENT OF THE PLATE MEMBERS FOR ABSORBING SHOCKS, SAID CYLINDRICAL ENDS OF THE CUSHIONING MEMBERS HAVING APERTURES REGISTERING WITH THE APERTURES IN THE PLATE MEMBERS FOR FLOW OF AIR INTO AND OUT OF THE CUSHIONING MEMBERS FOR COOLING SAID CUSHIONING MEMBERS, AND SAID CUSHIONING MEMBERS HAVING CIRCUMFERENTIAL RIBS WITH THE RIBS OF ONE MEMBER CONTACTING WITH THE RIBS OF ADJACENT MEMBERS UNDER SAID VARIABLE LOAD FOR STRENGTHENING SUPPORT OF THE CUSHIONING MEMBERS UNDER INCREASED RESILIENCY AFFORDED BY FLOW OF AIR THEREFROM. 